A rotation rate sensor is often attached to a rotatable object in order to measure a rotation rate of a rotary motion of the object. A conventional rotation rate sensor generally has at least one first oscillating mass and one second oscillating mass (seismic mass), to which linear oscillatory motions can be imparted by a drive system. The drive system is designed so that the first oscillating mass and the second oscillating mass oscillate with a 180-degree phase offset from one another (antiparallel). The oscillating motions of the first oscillating mass and the second oscillating mass are therefore often also referred to as antiphase motions.
If the object, having the rotation rate sensor disposed thereon, executes a rotary motion about a rotation axis not parallel to the oscillation direction of the oscillating masses, with simultaneous excitation of the two oscillating masses to perform their antiparallel oscillating motions, Coriolis forces then act on the two oscillating masses as they oscillate. The Coriolis forces cause the two oscillating masses each to be deflected perpendicular to their oscillation direction. The two oscillating masses are deflected in opposite directions because of the antiparallelism of the oscillating motions of the two oscillating masses.
The deflection of an oscillating mass is proportional to the Coriolis force acting on the oscillating mass. The deflection of the oscillating mass thus corresponds to the rotation rate of the rotary motion of the object. The rotation rate of the rotary motion can therefore be ascertained by evaluating the deflection of the oscillating mass.
To prevent an acceleration acting on the rotating object from resulting in an incorrectly determined rotation rate, a conventional rotation rate sensor is usually designed to detect the respective deflections of the two oscillating masses and compare them to one another. Only if the deflection of the first oscillating mass corresponds to the negative deflection of the second oscillating mass can it be assumed that the deflections of the two oscillating masses are based on Coriolis forces and not on an acceleration of the rotatable object.
A prerequisite for such an evaluation of the deflections of the two oscillating masses is, however, that the oscillating masses be reliably capable of being caused to perform antiparallel oscillating motions by the drive system. Manufacturing a drive system that approximately meets this prerequisite is, however, relative labor-intensive and comparatively costly. In addition, in a conventional rotation rate sensor deviations often occur from the desired antiparallelism of the oscillating motions of the two oscillating masses.